Agricultural land is a dynamic interwoven process of fostering growth and increasing of yield of useful plants. The first fertilizers were direct application of biosolids to increase crop yield. Early farmers did not understand alternative fertilizing methods and the long term effects of direct application on the surrounding soils. Early farms tended to have a smaller number of animals which in itself reduced the amount of biosolids being placed on soils. Larger farms today compound the environmental issues related to direct land application. As farms consolidate, biosolids are congregated and collected in a centralized location. Eventually, these biosolids find there way back to the nearby soils. Farms near creeks and streams have been found to have more serious environmental consequences. Even small farms near waterways today need to control runoff. In many states, farmers have been required to stop applying biosolids to lands in an environmentally sensitive area.
Biosolids can have positive impacts on farms. The mere mention of biosolids and manures brings up connotations of environmental concerns. It does not have to be that way. It is not the manures or it's contents that are bad. Even the phosphates in the biosolids themselves are nutrients that can be beneficial to crop yield. In fact, the nutrients would be highly sought after if their material characteristics were changed into traditional fertilizer granules. Granulation and drying of manures is becoming popular as a means of dealing with the problems of reapplying liquid and semisolid biosolids. However, the economics of this is more suitable to large corporate farms and cooperative efforts by local farms. The transportation costs to a regional granulation facility makes granulating a very difficult economic choice for many communities and smaller farmers. Marketing and finding outlets for these fertilizers is still another consideration. If additional costs are going to be applied to granulating, will there be a market for their product. Certainly, for the large farm this is so. But for the small farmer it is easy to understand why granulations is not a viable alternative. The present invention seeks out an alternative for the small farmer. The very same biosolid in a different form would certainly enhance the farmers crop yield while reducing or eliminating a very old environmental concern with regards to runoff and leaching of fertilizers, biosolids, and microbes. What was bad with biosolid in a liquid or semi solid state was the inability of the biosolids in their present state and material characteristics to stay where applied.
In recent years, where irrigation farming can be utilized, biosolids have been land applied and irrigation water with WSPAM applied to the soil either before or after to control the movement of biosolids. Where irrigation farming is not utilized, direct application occurs with increased control on the methods, timing and location of application.
Prior art patents have dealt with the material characteristics to reduce biosolid odors. Other patents have dealt with the material characteristics to dewater biosolids. Prior art patents have dealt with the material characteristics by drying biosolids. Still other patents have dealt with the characteristics by drying and forming granules from biosolids to make a fertilizer.
Water soluble polyacrylamide (WSPAMS) have been proposed as soil amendments for various agricultural purposes. Water soluble polymers, generically described as polyacrylamides (WSPAMs) appear to have a variety of beneficial soil amendment properties, including minimization of water run-off, erosion, and crusting, stabilization of soil structure, and binding of nutrients and microbes within soil.
Since the late 1980s there has been renewed interest in the use of water soluble polymers for soil physical improvement. Although Polyacrylamide (PAM) has been used for soil structure improvement since the 1940s and in agriculture since the 1950s the kinds of PAM used and the methods of application were different. Early PAMs had lower molecular weights than today's PAMS. They were applied to the soil at high rates, and were incorporated into the top soil by tillage.
In addition to the current interest in anionic PAMs as soil conditioners, they are widely used for other applications. PAMs are used for mineral and coal processing, petroleum production, paper making, water treating, food processing, and other miscellaneous applications.
Polyacrylamide (WSPAM) is a synthetic water-soluble polymer made from monomers of acrylamide. It binds soil particles in the water and irrigated furrow together, making particles larger so the water has a harder time washing them out of the field.
Polyacrylamides (WSPAM's) are compounds that hold on to nutrients and troublesome microbes before they can escape from soil and make their way to ponds, lakes, streams, rivers, and/or ground water. WSPAM has been shown to help keep nutrients, such as nitrogen and phosphorous in fertilizers, from traveling beyond the farm in irrigation runoff. Similarly, WSPAM helps keep disease causing microbes, like those in cow, pig, or fish manure, from being swept beyond the confines of farmyards or feedlots. WSPAM has four main physical characteristics. There are four main components to WSPAM: duration to dissolve, degree of charge, molecular weight, degree of branching.
High molecular weight and degree of branching are often inter-related. More branching results in a larger molecule and therefore a higher molecular weight. These molecules are more viscose in solution and often have more binding sites. The degree of charge refers to the strength of the ionic (positive and negative attraction) charge. The amount of time necessary to dissolve a WSPAM is dependent on chemical make-up, bonding, branching and particle size. The “work horse” polymers typically are water soluble polymers that have relatively high molecular weight and relatively high molecular charge density. They have a strong affinity to absorb water and enhance the germination of seeds. WSPAM used for erosion control has a slightly lower charge density than that used for seed germination and water retention. Polymers with a slightly lower charge density display the best results in precipitating out suspended solids in turbidity tests, thus their benefit to erosion control.
In the prior art, there is known a process for treating porcine excrement, so as to deodorize it. This process is more particularly known under the name “nitrification/denitrification treatment”. Thus, due to the presence of microorganisms whose growth is promoted by the oxygen in the air, an aerobic technique is used, the excrement is transformed into an odorless liquid which is constituted by a solution of elements and compounds comprising nitrogen, phosphorous, potassium and other components, while having an organic colloidal portion in suspension in this liquid medium. The ammoniacal nitrogen, which is the odor processing substance decreases by about 95% with this treatment. The porcine excrement thus treated can be used for spreading on fields without trouble from any odor.
U.S. Pat. No. 5,785,730 relates to a fertilizer comprising a dewatered solid agricultural nutrient. A method for preparing this fertilizer is provided including the steps of providing a raw agricultural waste to be treated, adding to the raw agricultural waste an effective amount of a composition comprising a quaternized amino methylated polyacrylamide polymer for separating the raw agricultural waste into a mixture having a separate clarified liquid portion and a separate dewatered nutrient solids portion, wherein the separated dewatered nutrient solids portion is a fertilizer, mixing the composition with the raw agricultural waste to facilitate the separation of the raw agricultural waste into the mixture, and subjecting the mixture to at least one mechanical separation means for segregating the separated clarified liquid portion from the fertilizer. An aqueous system comprising water, raw agricultural waste and a composition comprising a quaternized amino methylated polyacrylamide polymer is also disclosed. This prior art shows the physical alteration of the product to remove excess water while the present invention alters the physical characteristics to minimize movement of the biosolids prior to and after application.
U.S. Pat. No. 5,593,473 relates to a process for the treatment of porcine excrement, to transform it into fertilizer. To a liquid solution of porcine excrement, a solution of phosphorous pentoxide and potassium oxide is added in suitable proportions to obtain in the final product the desired ratio between nitrogen, phosphorous and potassium and as a function of the nature of the soil and of the type of application, after which the obtained solution is mixed with a product adapted to retain water, having the desired shape of the final product, so as to obtain a shaped and conditioned fertilizer, which is subjected to a drying treatment. Preferably, the water-retentive product is in the form of granules of polyacrylamide, which swell in water to a number of times their size when dry. The granules absorb the liquid very quickly, but releases it only slowly, so that they can swell and dry over and over to have a long effective life. In this prior art, the polyacrylamide mentioned is a co-polymer and not a water soluble polyacrylamide.
U.S. Pat. No. 5,776,350 relates to a method for separating raw agricultural waste into a liquid portion and a nutrient enriched solids portion. The method includes providing raw agricultural waste to be treated, adding to the raw agricultural waste an effective amount of a composition comprising a quaternized amino methylated polyacrylamide polymer for separating the raw agricultural waste into a mixture having a liquid portion and a nutrient solids portion, mixing the composition with the raw agricultural waste to facilitate the separation, and subjecting the mixture to at least one mechanical separation means for segregating the separated liquid portion from the separated nutrient solids portion. A method for transforming raw agricultural waste into a clarified liquid portion and a dewatered nutrient enriched solids portion is also taught. In this prior art, the polyacrylamide is used to separate the biosolids. However, the method of the present invention controls the movement of biosolids before, during, and after land application.